Positive control of colanic acid synthesis in Escherichia coli by rmpA and rmpB, two virulence‐plasmid genes of Kiebsiella pneumoniae
Positive control of colanic acid synthesis in Escherichia coli by rmpA and rmpB, two virulence‐plasmid genes of Kiebsiella pneumoniae
复制标题
肺炎克雷伯菌的两个毒力质粒基因rmpA和rmpB对大肠杆菌中可拉酸合成的正控制
DOI：
--
复制
发表时间：
1989
影响因子：
3.6
通讯作者：
P. Sansonetti
中科院分区：
文献类型：
--
作者：
Xavier Nassif;Nadine Honoré;T. Vasselon;Stewart T. Cole;P. Sansonetti
在肺炎Kiebsiella，黏液表型，这是一个毒力因子，不同于胶囊生产。它由一种被称为rmpA的质粒基因积极控制。当引入某些大肠杆菌菌株时，rmpA诱导粘液样表型的表达，这是由于在30°C而不是37°C时结肠酸过量产生的结果。在大肠杆菌中，粪酸的产生受三个基因的调控：rcsA和rcsB是正调控基因，rcsC是负调控基因。在这项工作中，我们提出的证据表明，rmpA基因补充了大肠杆菌rcsA，离子双突变体，而不是rcsA，离子+分离物。这表明rmpA表达一种类似rcsA的活性，并且与rcsA一样，在转录后水平受到Lon蛋白酶的负性控制。报道了rmpA的核苷酸序列。27千道尔顿的RcsA蛋白与15.5千道尔顿的RmpA蛋白的氨基酸序列无同源性。另一个基因rmpB已在肺炎克雷伯菌毒力质粒上被发现，并编码一个37千道尔顿的蛋白，该基因是大肠杆菌recA分离株在30°C下完全表达rmpA所必需的。尽管rmpB与rmpA紧密相连，但它并不存在于相同的转录单位上。这些结果表明，至少在大肠杆菌中，肺炎克雷伯菌毒力基因rmpA对结肠酸合成的诱导是受RecA网络通过rmpB控制的，rmpB可能是rmpA的正调节因子。我们得出结论，这些质粒基因可能在肺炎克雷伯菌中作为调节基因控制黏液表型，而黏液表型本身是由染色体编码的。
In Kiebsiella pneumoniae, the mucoid phenotype, which is a virulence factor, is distinct from capsule production. It is positively controlled by a plasmid gene, designated rmpA. When introduced into certain Escherichia coli strains, rmpA induces expression of a mucoid phenotype, which results from overproduction of colanic acid at 30° C but not at 37°C. In E. coli, production of colanic acid is regulated by three genes: rcsA and rcsB which act as positive regulators, and rcsC which is a negative effector. In this work we present evidence that the rmpA gene complemented an rcsA, Ion double mutant of E. coli, but not an rcsA, ion+ isolate. This leads to the suggestion that rmpA expressed an rcsA‐like activity and like rcsA, was negatively controlled at post‐transcriptional level by the Lon protease. The nucleotide sequence of rmpA is reported. No homology could be found between the 27 kiloDalton RcsA protein and the deduced amino acid sequence of the 15.5 kiloDalton RmpA protein. Another gene, rmpB, which was required in E. coli recA isolates for full expression of rmpA at 30° C, has been identified on the K. pneumoniae virulence plasmid and shown to encode a 37 kiloDalton protein. Although rmpB was closely linked to rmpA, it was not present on the same transcriptional unit. These results suggested that induction of colanic acid synthesis by the K. pneumoniae virulence gene rmpA, was, at least in E. coli, under the control of the RecA network via rmpB, which may act as a positive regulator of rmpA. We conclude that these plasmid genes may function in K. pneumoniae as regulatory genes controlling the mucoid phenotype, which is itself encoded by the chromosome.
DOI：
10.1073/pnas.78.8.4728
发表时间：
1981-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
CHARETTE, MF;HENDERSON, GW;MARKOVITZ, A
通讯作者：
MARKOVITZ, A